1. Technical Field
The present invention relates to the field of illuminated displays. More specifically, the invention relates to generating color graphics within an illuminated display.
2. Background of the Invention
Various types of lights can be used as the light source in illuminated displays, such as a backlit display, with the choice often dictated by the industry and the application in which the back light is going to be utilized. For instance, in the automotive industry, light emitting diodes (LEDs) are commonly-used in backlit displays due to their size, durability, longevity and energy consumption properties. However, due to their nature, it is difficult to manufacture LEDs that emit light over a large spectrum of frequencies, which in turn makes their use in backlit displays difficult. For instance, commonly used blue LEDs do not emit energy of the appropriate wavelengths required to properly illuminate the colors yellow, orange or red in a backlit display. Greater frequency spectrum LEDs do exist, but commonly-available white LEDs tend to be expensive and tend to have varying colors and wavelengths in their emitted light.
Prior art structures used to control backlighting of graphics often rely on coating a light cover with multiple layers of light-modifying materials to generate the desired visual effect of the graphics. For example, as shown in FIG. 1, a light source 10 may be covered by a cover 15 made of a substrate 20 and a diffusing layer 22 to diffuse the emitted light. A fluorescing layer 24 and a graphics color layer 26 are deposited on top of the diffusing layer 22 to absorb light energy that does not correspond to the desired color. An opaque topcoat 28 with an opening 30 in the shape of the desired graphic allows the light escaping the cover 15 to reach the viewer. This complicated layered structure, however, requires many manufacturing steps, introducing a high degree of variability between components.
There is a desire for a simplified apparatus and method that can control colors in an illuminated display.